Accuracy of an infrared LED device to measure heart rate and energy expenditure during rest and exercise

J Sports Sci. 2011 Dec;29(15):1645-53. doi: 10.1080/02640414.2011.609899. Epub 2011 Oct 13.


The purpose of this study was to examine the accuracy of the ePulse Personal Fitness Assistant, a forearm-worn device that provides measures of heart rate and estimates energy expenditure. Forty-six participants engaged in 4-minute periods of standing, 2.0 mph walking, 3.5 mph walking, 4.5 mph jogging, and 6.0 mph running. Heart rate and energy expenditure were simultaneously recorded at 60-second intervals using the ePulse, an electrocardiogram (EKG), and indirect calorimetry. The heart rates obtained from the ePulse were highly correlated (intraclass correlation coefficients [ICCs] ≥0.85) with those from the EKG during all conditions. The typical errors progressively increased with increasing exercise intensity but were <5 bpm only during rest and 2.0 mph. Energy expenditure from the ePulse was poorly correlated with indirect calorimetry (ICCs: 0.01-0.36) and the typical errors for energy expenditure ranged from 0.69-2.97 kcal · min(-1), progressively increasing with exercise intensity. These data suggest that the ePulse Personal Fitness Assistant is a valid device for monitoring heart rate at rest and low-intensity exercise, but becomes less accurate as exercise intensity increases. However, it does not appear to be a valid device to estimate energy expenditure during exercise.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Calorimetry, Indirect / methods
  • Electrocardiography
  • Energy Metabolism / physiology*
  • Exercise / physiology*
  • Exercise Test / instrumentation*
  • Exercise Test / methods
  • Female
  • Heart Rate*
  • Humans
  • Infrared Rays
  • Light
  • Male
  • Monitoring, Ambulatory / instrumentation*
  • Monitoring, Ambulatory / methods
  • Physical Exertion / physiology*
  • Posture
  • Pulse
  • Reproducibility of Results
  • Rest / physiology*
  • Running / physiology
  • Walking / physiology
  • Young Adult